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V-grooving of PVD-coated stainless gives architectural metal fabricator a durable alternative

Situation

Architectural firm McBains recently was hired to renovate a dilapidated office building by refreshing the interior and providing a new design for the entrance. It considered using a bronze-colored electroplated and sandblasted stainless steel but was concerned that the electroplated finish would be adversely affected by weather.

Architectural metal fabricator John Desmond Ltd. suggested a PVD-coated stainless that provided the aesthetic appeal of solid bronze without the weight, as well as a 12-year guarantee.

The original specification for the brise soleil fins was for solid stainless steel bar for a substantial look, but the steel would have been very heavy to hang from the canopy, and the fins would have deflected under their own weight. In addition, those bars would have had to be clad to achieve the bronze look.

Resolution

Alex Pashouros, project manager at John Desmond Ltd., suggested fabricating the brise soleil, canopy, and column from PVD-coated, colored stainless steel that was V-grooved and folded to appear as solid material. A current trend is to use wall panels and interior components with new colors and textures. Colored stainless is created with the physical vapor deposition (PVD) process, which creates a thin film available in a variety of colors.

The fabricator used V-grooving machines from Hydrapower, which enable sheet metal to be formed with a sharp outside corner on the bend. Typically, a V groove is machined on the inside of the bend line, and when the metal is bent along that line, a sharp corner is achieved. The machines can accommodate sheets up to 0.5 in. thick and 20 ft. long, making a variety of grooves other than vees.

A V groover can finish a 10-ft. by 0.045-in.-deep groove in 16-ga. stainless steel in about 5 sec. A complete panel with four grooves at 10 ft. long can be processed in a cycle time of about 1 min. Hydrapower’s software allows the fabricator to activate a pause function to bring the sheet to the front, where the clamps release and the operator can turn it 90 degrees to run grooves in the perpendicular direction. This feature also is used when a sheet is grooved on both sides.

The fabricator worked under restricted time scales and access, so it was essential that while on-site all construction work proceeded smoothly and without any delays.

“Building off-site was the only way to approach this project,” explained Pashouros. “By completely building the structures off-site, this reduced the risk of on-site delays and disruption. All components were fabricated in our workshops, which allowed the structures to be inspected by the design team and the contractors.”

The canopy structure was transported to the site in 26 sections each weighing 330 lbs. The brise soleil was built to its full height of 13 ft. in the workshop, then dismantled and taken to the site. The verticals were solid with aluminum inserts clad in the PVD sheet. The fins were created from the PVD sheet and strengthened with stainless steel ribs, which were bonded on together with the end caps. The 19.6-ft.-high column had to be built in two sections. It was laid down on its back and the whole column clad in the workshop before being dismantled and taken to the site.

For the brise soleil, canopy, and column, the fabricator used 45 sheets of 316 stainless steel, each 8 by 4 ft. and 0.06 in. thick. The sheets were colored through the PVD process and then embossed. Fabricating took four weeks, and the installation required another eight weeks.

Hydrapower Intl.

www.hydrapower-intl.com